There has been enormous hype and publicity surrounding self-driving cars, and companies around the world are pursuing the technology. But one corporation, Ford, has come clean and is now saying we won’t see them anytime soon. The reality of the complexity of self-driving vehicles has set in. Even Waymo, which has spent billions pursuing the autonomous car, hasn’t rolled out its self-driving machines except in isolated spots in Arizona. The hype got ahead of itself. Now, companies must do the hard work of making self-driving practical. That may be impossible. There are too many conditions on roadways from the elements — fog, rain, snow, brilliant sunshine — to unaccountable maneuvers of other drivers. It would be OK if everyone drove safely to begin with, but they don’t. Technology has to anticipate the unknowable and be ready to respond. That is a tall order. Ford should be commended for being open about the difficulties — a first step in finding solutions.